SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '6b3dbb9e84e7d629a963348b5a668fbc2f83b9039e4641e8d0c4bdce827fddb5' 
  AND token = '9UF2BHWrOyWIEg96uiu0NzNqnsTN70SwVyREZ8GXUK0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}